Answer:
(2x - 5)(2x +5)
Step-by-step explanation:
4x^2 is a perfect square with a square root of 2x, and 25 is also a perfect square with a square root of 5. The difference of two perfect squares a and b can be written as . So, 4x^2 - 25 can be factored into (2x-5)(2x+5).
Hope that helped! ;)
Answer:
The true mean contents of the cans being filled by this machine with 95% confidence is between 11.891 ounces and 11.949 ounces.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 35 - 1 = 34
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 34 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.032
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 11.92 - 0.029 = 11.891 ounces.
The upper end of the interval is the sample mean added to M. So it is 11.92 + 0.029 = 11.949 ounces.
The true mean contents of the cans being filled by this machine with 95% confidence is between 11.891 ounces and 11.949 ounces.
(2.4+1.3)*3.89=14.39
The total amount Kristin spent is $14.39
Answer:
A sample size of 6755 or higher would be appropriate.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
The margin of error M is given by:
90% confidence level
So , z is the value of Z that has a pvalue of , so .
52% of Independents in the sample opposed the public option.
This means that
If we wanted to estimate this number to within 1% with 90% confidence, what would be an appropriate sample size?
Sample size of size n or higher when . So
A sample size of 6755 or higher would be appropriate.
Hey there!
c² = 5c
Subtract 5c from both sides:
c² - 5c = 5c - 5c
Simplify :
c² - 5c = 0
c = 5 , c = 0